Linux kernel 3.7 has been released. This release includes support for the new ARM 64 bit architecture, ARM multiplatform support - the ability to boot into different ARM systems using the same kernel; support for cryptographically signed kernel modules; Btrfs support for disabling copy-on-write on a per-file basis using chattr; faster Btrfs fsync(); a new experimental "perf trace" tool modeled after strace; support for the TCP Fast Open feature in the server side; experimental SMBv2 protocol support used by modern Windows systems; stable NFS 4.1 and parallel NFS; the vxlan tunneling protocol that allows to transfer Layer 2 ethernet packets over UDP; and support for the Intel "supervisor mode access prevention" security feature. Many small features and new drivers and fixes are also available. Here's the full list of changes.